British Patent Publication No. 2,081,711 or Unexamined European Patent Publication No. 70,170 discloses tylosin compounds having only mycaminose or desosamine as sugar component. These publications disclose tylosin compounds wherein the 23-position carbon atom has a substituent such as a halogen atom, a hydroxyl group, an alkanoyloxy group, ##STR2## (wherein R.sup.6 represents a hydrogen atom or a lower alkyl group which may be substituted by a hydroxyl group, R.sup.7 represents a hydrogen atom, an alkyl group which may be substituted by a hydroxyl group, an aryl group, an aralkyl group, etc.), etc.
The compounds of this invention of the formula (I) are novel compounds having excellent antibacterial activity, and have a characteristic in that the 23-position carbon atom has a substituent selected from a lower alkyl group, an aryl group, a lower alkenyl group, or a lower alkynyl group.